Effect of land use on the distribution and abundance of native fish in tributaries of the Waikato River in the Hakarimata Range, North Island, New Zealand

Abstract

The effect of land use on fish community structure was examined at fifty-five sites in tributaries draining exotic, indigenous forest and pastoral catchments in the Hakarimata range in March and April 1987. Using a model containing percentage woody debris, temperature, and substrate coarseness, 76% of the sites were classified into correct land uses by discriminant analysis. This indicated that differences in stream habitat, and hence of the fish fauna, were related to effects of changed land use rather than other confounding physical or geographical features of the streams in the catchments. Tributaries in indigenous forest were numerically dominated by banded kokopu (Galaxias fasciatus) and longfinned eel (Anguilla dieffenbachii), with redfinned bully (Gobiomorphus huttoni) and giant kokopu (G. argenteus) occasionally being caught. Pastoral streams below the forest generally supported higher densities and contained more species including the forested species above, Cran's bully (G. basalis), and shortfinned eel (A. australis). As the amount of indigenous forest in the catchment decreased the fauna became less abundant and less diverse and was dominated by both species of eel and Cran's bully.

Use of in‐stream cover types by adult banded kokopu (Galaxias fasciatus) in first‐order North Island, New Zealand, streams

“…Its migratory juveniles form part of the whitebait fishery at river mouths (McDowall & Eldon 1980;Rowe et al 1992) and, although it is still common throughout New Zealand, its habitat has been greatly reduced by changes in land use from native forest to pasture (Hanchet 1990;Rowe et al 1999). As a consequence, its contribution to the whitebait fishery is now minor, and is probably much lower than it was historically (Rowe et al 1999).…”

Age and growth of longfinned eels (Anguilla dieffenbachii) in pastoral and forested streams in the Waikato River basin, and in two hydroelectric lakes in the North Island, New Zealand

“…Streams in native forest have lower food availability than pastoral streams because fish and invertebrate biomass may be low (Taylor 1988;Hanchet 1990;Quinn & Hickey 1990), and vegetation inhibits overland run-off. Low abundance of fish in upper catchments probably limits piscivory by longfinned eels, and could impair growth compared with lower catchments where fish are more plentiful.…”

“…Higher gradients may also cause longfinned eels to expend more energy to maintain their position against faster flows, further restricting growth. Galaxid species occur in forested streams, generally at low densities (Hanchet 1990), and where present together with longfinned eels must increase competition for food.…”

Structure of endemic fish assemblages in the upper Yangtze River Basin

“…Studies in the last decade have shown that variation in catchment land cover plays an important role in the distribution and movement of fish across different aquatic ecosystems (Hanchet, 1990;Sutherland et al, 2002;Strayer et al, 2003;Allan, 2004;Singkran and Meixler, 2008). These may indirectly affect fish assemblage distributions by altering fish habitats in terms of light intensity, organic matter, nutrients or sediment load, and directly by the interactions with other anthropogenic drivers (e.g.…”